Modification of policing methods to make them more TCP-friendly

摘要

Various improvements are provided for prior art policing methods, including token bucket methods and virtual time policing methods. Some preferred methods of the invention involve assigning a non-zero drop probability even when the packet would otherwise have been transmitted according to a prior art policing method. For example, a non-zero drop probability may be assigned even when there are sufficient tokens in a token bucket to allow transmission of the packet. A non-zero drop probability may be assigned, for example, when a token bucket level is at or below a predetermined threshold or according to a rate at which a token bucket is being emptied. Some implementations involve treating a token bucket as a virtual queue wherein the number of free elements in the virtual queue is proportional to the number of remaining tokens in the token bucket. Such implementations may involve predicting a future virtual queue size according to a previous virtual queue size and using this predicted value to calculate a drop probability.